private static void removeTrailingSpaces(final Document document, final int startOffset) {
      int endOffset = startOffset;

      final CharSequence charsSequence = document.getCharsSequence();

      for (int i = startOffset; i < charsSequence.length(); i++) {
        final char c = charsSequence.charAt(i);
        endOffset = i;
        if (c == '\n') {
          break;
        }
        if (c != ' ' && c != '\t') {
          return;
        }
      }

      document.deleteString(startOffset, endOffset);
    }
    private void generateJavadoc(CodeDocumentationAwareCommenter commenter)
        throws IncorrectOperationException {
      CodeInsightSettings settings = CodeInsightSettings.getInstance();
      StringBuilder buffer = new StringBuilder();
      final String docCommentLinePrefix = commenter.getDocumentationCommentLinePrefix();
      if (docCommentLinePrefix == null) {
        return;
      }

      // There are at least two approaches for completing javadoc in case there is a text between
      // current caret position and line end:
      //     1. Move that tail text below the javadoc. Use-case:
      //         Before:
      //             /**<caret>public void foo() {}
      //         After:
      //             /**
      //              */
      //             public void foo() {}
      //     2. Move the tail text inside the javadoc. Use-case:
      //          Before:
      //             /**This is <caret>javadoc description
      //          After:
      //             /** This is
      //              * javadoc description
      //              */
      // The later is most relevant when we have 'auto wrap when typing reaches right margin' option
      // set, i.e. user starts javadoc
      // and types until right margin is reached. We want the wrapped text tail to be located inside
      // javadoc and continue typing
      // inside it. So, we have a control flow branch below that does the trick.
      buffer.append(docCommentLinePrefix);
      if (DataManager.getInstance()
              .loadFromDataContext(
                  myDataContext, AutoHardWrapHandler.AUTO_WRAP_LINE_IN_PROGRESS_KEY)
          == Boolean.TRUE) {
        myDocument.insertString(myOffset, buffer);

        // We create new buffer here because the one referenced by current 'buffer' variable value
        // may be already referenced at another
        // place (e.g. 'undo' processing stuff).
        buffer =
            new StringBuilder(LINE_SEPARATOR).append(commenter.getDocumentationCommentSuffix());
        int line = myDocument.getLineNumber(myOffset);
        myOffset = myDocument.getLineEndOffset(line);
      } else {
        buffer.append(LINE_SEPARATOR);
        buffer.append(commenter.getDocumentationCommentSuffix());
      }

      PsiComment comment = createComment(buffer, settings);
      if (comment == null) {
        return;
      }

      myOffset = comment.getTextRange().getStartOffset();
      CharSequence text = myDocument.getCharsSequence();
      myOffset = CharArrayUtil.shiftForwardUntil(text, myOffset, LINE_SEPARATOR);
      myOffset = CharArrayUtil.shiftForward(text, myOffset, LINE_SEPARATOR);
      myOffset = CharArrayUtil.shiftForwardUntil(text, myOffset, docCommentLinePrefix) + 1;
      removeTrailingSpaces(myDocument, myOffset);

      if (!CodeStyleSettingsManager.getSettings(getProject()).JD_LEADING_ASTERISKS_ARE_ENABLED) {
        LOG.assertTrue(
            CharArrayUtil.regionMatches(
                myDocument.getCharsSequence(),
                myOffset - docCommentLinePrefix.length(),
                docCommentLinePrefix));
        myDocument.deleteString(myOffset - docCommentLinePrefix.length(), myOffset);
        myOffset--;
      } else {
        myDocument.insertString(myOffset, " ");
        myOffset++;
      }

      PsiDocumentManager.getInstance(getProject()).commitAllDocuments();
    }